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Persistent Fe moments in the normal-state collapsed-tetragonal phase of the pressure-induced superconductor<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Ca</mml:mi><mml:mrow><mml:mn>0.67</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Sr</mml:mi><mml:mrow><mml:mn>0.33</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi>Fe</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>As</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>
Using nonresonant Fe $K\ensuremath{\beta}$ x-ray emission spectroscopy, we reveal that Sr substitution into ${\mathrm{CaFe}}_{2}{\mathrm{As}}_{2}$ decouples the Fe moment from the volume collapse transition, yielding a collapsed-tetragonal, paramagnetic normal state out of which superconductivity develops. X-ray diffraction measurements implicate the $c$-axis lattice parameter as the controlling criterion for the Fe moment, …